mccormack



Fay. 1.

W. J. MQUORMAOKL Screw Cutting Die.

Patented Sept. 21, 1880.

N.FETERS. PNOTQxLiTHOGRAPHER WA m UNITED STATES ATENT oases.

WILLIAM J. MOOOR-MAOK, OF PAIGNTON, ENGLAND.

SCREW-CUTTING D IE.

SPECIFICATION forming part of Letters Patent No. 232,533, dated September 21, 1880.

Application filed April 23, 1880. (No model.) Patented in England May 30, 1879.

derstood, I will proceed to describe the same by reference to the accompanying drawings, in which- Figure 1 is a side view, partly in section, of

my improved stock and dies; Fig. 2, plan of same, partly in section; Fig. 3, view of an attachment employed with the stock and dies when screwing light brass tubes.

In Figs. 1 and 2, A represents the stock or die-plate, which is formed with a central hole, a, into which open-four holes or openings passingedgewise through the stockAfrom theends, and in a nearly-radial direction with the center of the hole in the stock, as shown in Fig. 2.

B B are the dies or bits, which are provided with threads orteeth at both ends, so that they may be reversed, and they are preferably formed of round steel, which is a great advantage. The said dies B pass into the hereinbefore-described radial holes, and when the dies 13 are made of round metal the said holes are severally provided with a key, 0, which is passed into such hole through the stock A, and the dies are made with a longitudinal groove 01' keyway, G, into which the inner ends of such keys project, so that the dies B are held perfectly firm, and the grooves permit the ad justment of the dies to any desired position, however minute or delicate. The .dies, however, may be made, of other shape in their cross-section, of steel, the radial holes in the stock corresponding in shape, and in this case no key or keyway will be required.

Each end of the stock or die-plate A is formed with a screw-threaded projection, D,

inward and held to the desired position, or relieved from such hold, a loose collar, F, of brass or other suitable metal, being placed between the ends of the dies and the screw-ferrule, as shown. Into the ends of the said projections D of the stock are screwed the han-. dles G, for operating the apparatus, and these handles being removable render the apparatus very portable. The placing of the dies radially, or nearly so, and their being reversible, allows ot' screwing with each end of the dies two or more difterentsized pipes with each tool and without the aid of other dies.

When screwing light brass tubes of the lar'ger sizes I employ'th'e movable attachment or device shown in Fig. 3. This attachment consists of a saddle-plate, H, through the center of which passes an expanding tubular core, I, tapered inside and slotted at the lower end, and provided on top with a set screw, K, which, when turned, forces down a conicalpointed pin, whereby an expanding movement is obtained. The lower end is also provided with a movable collar, J, of box-wood or other suitable material, turned to fit the interior diameter ofthe various sizes of tube.

To fix the attachment, the saddle-plate His attached centrally on the top of the stock A by means of two setscrews; then, by turning the thumb-screw K, as hereinbefore described, the core I will be expanded and will expand the collar J tightly in the tube to be screwed, and the core I and saddle-plate H, being provided with the ordinary gas-pipe thread, the dies are propelled and steadied, thus insuring true threads on tubes of large diameter.

Having thus described my said invention, and the manner of performing the same, I wish it to be understood that I do not confinemyself to the precise details herein laid down and shown in the drawings, as the same may be varied without departing from the peculiar character of my invention; but

What I do claim is- 1. The screw-cutter stock A, constructed as described, to wit, having at each end a projection, D, screw threaded on its exterior, adapting it to receive a threaded sleeve, and screwthreaded on its interior to receive a removable handle, and provided at each end with two bit-holes, located, respectively, at each shown in Fig. 3 of the drawings, and arranged and operating in the manner and for the purposes hereinbefore described.

4. In a screw-stock or die-plate constructed as hereinbefore described, reversible dies made of round steel and provided with longitudinal keyways or grooves combined with holdingkeys 0, as shown and described.

WILLIAM JOHN MCOORMAGK.

WVitnesses W. B. BEYNON, J AMEs EDWARD WELCH. 

